As will be appreciated by those skilled in the art, the removal of crab meat from the shell structure of the crab body is still primarily performed by hand whereby each crab is handled several times as the meat is extracted. As is well known, although great care may be taken during the hand picking of the crab meat, much meat is left in the shell structure, and a great amount of shell also finds its way into the meat.
In the past, numerous devices have been patented and/or developed which attempted to solve the problem of removing crab meat from the shell structure of the crab. For example, it has been known in the past to use centrifugal or spinning of crab bodies so as to extract the crab meat. For example, U.S. Pat. No. 1,175,037 issued Mar. 14, 1916 is a very early example of such centrifugal spinning to remove crab meat. In that patent, there is seen a centrifugal retainer which has semicircular receiving pans or receptacles for the meat as well as supports or racks for holding the sections of the animal to be shelled. U.S. Pat. No. 1,520,190 issued Dec. 23, 1924 and entitled "EXTRACTING MACHINE" shows a method of extracting meat from shell fish whereby the holder and meat catching means are spun as a unit. Another concept in centrifugal extraction of crab meat includes U.S. Pat. No. 1,655,583 entitled "METHOD AND APPARATUS FOR SHELLING CRUSTACEAN" which provides a motor driven rotating pan having clamps on the underside to secure the crab body's sections so that during the spinning of the crab meat, the sections will be retained and the meat forced out by the centrifugal action.
Another U.S. Pat. No. 2,104,072 entitled "PROCESS OF AN APPARATUS FOR TREATING CRUSTACEA" uses a rotatably driven bowl. In the process of preparing the meat of the crab or other crustacea, the crustacea is subjected to centrifugal action in order to separate the meat from the shell. The same centrifugal action is also used to wash the separated meat.
U.S. Pat. No. 2,522,578 entitled "RECOVERY OF CRAB MEAT" shows a coring machine which processes the crab by producing a crab body core by making a circular cut through the ventral surface of the crab body through the meat and skeletal parts within the body. After removing the core from the crab the meat is extracted by centrifugal action. Another patent which cores and centrifugally removes crab meat is entitled "APPARATUS FOR RECOVERY OF CRAB MEAT" and has U.S. Pat. No. 2,525,604. Still another U.S. Pat. No. 2,771,630 is entitled "CRAB MEAT EXTRACTOR". According to the teachings of that patent, after coring a section of the crab body from the crab, the cored section is rotated about its axis in order to remove the crab meat.
Still another U.S. Pat. No. 3,229,325 entitled "APPARATUS FOR EXTRACTING CRAB MEAT" discloses a centrifugal device having a carriage for holding a plurality of crab body sections. The carriage includes a spinning basket which features a first and second set of plurality of upstanding and generally parallel pins which are supported at their lower ends from a spinning base with pins being arranged in circular patterns and disposed concentrically about the axis of rotation. The second set of the pins is disposed radially inward of the first set. The crabs are placed between the inner and outer sets of pins, and are held down by an annular plate which has apertures that allow the pins to pass through.
A more recent U.S. Pat. No. 3,597,792 entitled "CRAB MEAT EXTRACTOR APPARATUS AND METHOD" discloses a machine and method for extracting meat from the body shells of crabs by the employment of centrifugal force. This device is characterized by structures and procedures which permit operation at different speeds operative to selectively and successively extract the more valuable, relatively large meat sections in substantially unbroken condition. This process is then followed by extraction of the smaller, less valuable flake meat sections by centrifugal rotation at a higher speed. Part of the apparatus utilizes a rotating tray which carries a plurality of radial extending, angularly spaced clips which are pivoted on upstanding hinged lugs and biased by means of a spring to normally urge the forward end of the clip into a closed position. The spring biased clips and cooperating teeth function to securely hold crab half-bodies and restrain them against centrifugal force during rotation of the trays. A single crab half body is secured by each of the clamps.
In another U.S. Pat. No. 3,548,449 entitled "CRAB MEAT EXTRACTION METHOD" there is described a method for removing crab meat from crab body sections which uses two rotating speeds as part of the method. The first rotating speed has a lower speed to remove larger lump sections of crab meat, and a higher speed rotation which rotates the crab body sections to remove the smaller pieces or flake meat.
In addition, U.S. patent application having Ser. No. 593,035 filed on Mar. 23, 1984 by Alfred R. Guglielmo and W. Lee Lockerby, and which application is assigned to the same assignee as the present invention, discloses a centrifugal device for removing crab meat from halves of crab bodies. According to this machine, there are four individual individual crab receiving areas which cooperate with individual meat receiving receptacles. The crab body halves are placed against inwardly leaning pins located in very close proximity to the supported meat receptacles. The crab is placed with the cut middle section against the sloping pins. A hinged lid is then rotated in position to cover both the crab body and the meat receptacle to reduce windage. The machine is then rotationally accelerated to the desired rotational speed for extracting the crab meat. This technique provides a good quality of crab meat with reduced shell, but always requires the preparation of the crab bodies in halves and also is somewhat difficult to load and unload.
Thus a review of the prior art patents and available devices reveals that to date there has not been a simple and inexpensive process which can rapidly process the crab bodies with minimum handling, and which reduces the amount of shell in the meat to an absolute minimum. Therefore, it is an object of this invention to provide apparatus and methods of extracting crab meat without breaking the shell structure.
It is still another object of the present invention to provide apparatus and method for extracting crab meat from the shell structure of the crab body which meat contains a minimal amount of broken shell particles.
It is also an object of the present invention to provide an apparatus and methods which allows the rapid loading and unloading of the centrifugal machine of this invention.
Other objects and advantages will be obvious, and will in part appear hereinafter, and will be accomplished by the present invention which provides the apparatus and method for centrifugally extracting meat from prepared crab bodies. According to the invention, there is provided a base housing which supports and contains a rotating drive means. There is also included a crab body holding means, such as a carrousel, which in a preferred embodiment is rotatably supported and releasably attached to the rotating drive means. The carrousel includes a spin axis and has the primary purpose of providing a means for restraining the shell structure of a crab body in a select orientation during rotation. The crab body is maintained in position with opened meat cavities located opposite a port or meat passage way located at the perimeter of the holding means. The crab body, prior to being subjected to the centrifugal forces of the machine, may be prepared so as to have openings through the shell structure to meat cavities not normally open such that when the holding means spins around the spin axis, the centrifugal forces created on the crab bodies extracts the crab meat through the openings from the restrained shell structure. The centrifugal forces also propel the extracted meat from the holding means through the perimeter port.
In a preferred embodiment, there is also included a spinning meat receiving compartment adjacent the perimeter port which collects the extracted meat as it is propelled through the port and which has a spin axis coaxially and common with the rotatably holding means. The meat receiving compartment or ring is located at a radial distance from the common axis of the holding means which radial distance is greater than the outside perimeter of the holding means. The meat receiving compartment or ring is supported and driven by the rotating drive means and in a preferred embodiment is also releasably attached to the drive means. The receiving compartment and the holding means also cooperate with each other so as to maintain a relative position with each other during the spinning process. There also is included a means for controlling the rotating drive means such that the combination meat receiving compartment and holding means may be accelerated from a non-spinning or "stopped" condition to a maximum rotating speed in a specific or first selected time period. Also included is a brake means for stopping the rotation of the combination in a very short time period.
In a preferred embodiment, the holding means further includes a crab body support structure which is located proximate the perimeter ports and which support structure includes a receiving cup shaped to conform to the inner shell structure of the crab such that when the crab is spun with the belly shell of the crab perpendicular to the radius of the centrifugal force and facing in toward the spin axis, the meat is extracted through the center sections of the prepared whole crab.